[Zope] ParsedXML performance (was: Squishdot News)

Karl Anderson karl@digicool.com
15 May 2001 12:49:50 -0700


"Joachim Werner" <joe@iuveno-net.de> writes:

> > > (Does Zope 2.3.2+ ship with a fast XML parser? If so, what's it called
> > > and where do I import it from?)
> 
> Just because you mentioned "fast": Am I doing any thing wrong, or is
> ParsedXML extremely slow? The tests I did were not really reliable, but even
> with a fast Pentium III machine (800 MHz, a lot of RAM), switching between
> the edit view and the DOM view can take a couple of seconds for me. And
> that's for really simple, ten-line test XML documents.

That's way slower than what I've seen.  The edit or DOM tree view of a
ten-line XML document should not be noticably slower than your average
Zope management page on a fast machine.  I test on a 666 Mhz box with
lots of other stuff going on and don't see this.

If you're looking at the *collapsed* DOM tree view, ParsedXML isn't
doing much at all, just getting the document element node, so slowness
that you see there probably isn't ParsedXML.

Access these pages and some DTML documents or whatever *on the same
server with the same load* with wget or ab, and time the results.
What is the difference?

That being said, printing the XML is slow, which is why the default
view isn't the edit window.  I recommend cacheing when you're using the
XML from ParsedXML.  And also, yes, ParsedXML proxies the DOM in an
clunky way, which is why it is often a good idea to use the
proxied DOM when speed is an issue.  It's a compromise.  ParsedXML's
proxy layer has the features, the proxied DOM has the speed, but is
nothing but DOM.

-- 
Karl Anderson                          karl@digicool.com